1. Field of the Invention
This invention relates to indicia encoding systems and, more particularly, to a system including a camera with a lenticular lens that has a rotational mode synchronized to a rotational mode of the indicia for producing a picture of scrambled or coded indicia.
2. Description of the Prior Art
With the proliferation of credit and identification cards, and especially with the energence of cash retrieval cards associated with electronic fund transfer systems that can allow ready and complete access to financial accounts, a need arises to protect the cardholder from unauthorized use of the card. Generally, information such as account numbers and signature styles are readily available from the face of these cards, and especially in the case of most credit cards no protection is provided from unauthorized use of the account number or duplication of the signature style. Consequently, if this information could be encoded, and readily decoded for authorized use only,the losses due to unauthorized use could be reduced.
A present method for encoding such indicia, which is proving to be of increasing usefulness, is incorporation of a graticule, such as a lenticular lens, into a photographic system. A variety of lenticular lenses are available. One type lens has, for example, a plurality of tiny corrugations embossed therein. Another type of lens comprises a multiple array lens. Both lenses encode the light patterns projected by the photographic system onto photosensitive film. This encoded pictorial representation of the information can readily be decoded by placing the representation into a viewer that has been provided with a lenticular lens similar to the one in the photographic system. Thus, encoded representation of a signature and an account number can, for example, be affixed to a banking card and used during banking transactions for signature and account verification purposes. Such indicia encoding and decoding devices are, for example, discussed in U.S. Pat. Nos. 3,178,993 and 3,676,000.
A method for providing further encoding comprises the use of a lenticular lens in conjunction with an objective lens and photosensitive film, any combination of which can be placed in motion relative to one another to create the encoded pictoral representation of the indicia. An example of such a system can be found in U.S. Pat. No. 3,937,565. In addition, camera type apparatus, that are employed in such a method can be found in U.S. Pat Nos. 3,524,395 and 3,769,890.
An indicia encoding system developed for the Girard Bank of Philadelphia incorporates various aspects of the above-referenced patents. The Girard system includes a camera with a lenticular lens mounted to the film holder of the camera. The film holder is designed to move relative to the objective lens of the camera as an exposure is made and to index after each exposure so that in cooperation with a shutter, a plurality of exposures can be taken on each piece of photosensitive film. Further, the indicia being encoded is placed in a pivotally mounted holder that pivots in synchronism with the film holder during each exposure to provide for, in cooperation with the lenticular lens, indicia encoding.
The Girard system suffers from several disadvantages. One of these disadvantages is that the mounting apparatus that provides for the motion of the film holder relative to the objective lens and the indexing motion between exposures is unreliable, in that it has a tendency to bind up, and thus render the system inoperable.
Another disadvantage is that this system produces an encoded picture that is the same size as the original indicia. Thus, the original indicia has to be initially small enough so as to be affixable to a credit card. However, it has proven inconvenient to provide space on standard bank or credit card application forms for redundant indicia of reduced size suitable for encoding. Additionally, the indicia, being of reduced size, can not always be accurately coded so that during decoding, the indicia is not always clearly and accurately reproduced. Moreover, with small indicia, more light and/or time is required to properly expose the photosensitive film.
Finally, the Girard system encoded all of the indicia exposed to the photosensitive film. Consequently, the encoded indicia, after being affixed to the card, had to be viewed through a decoding viewer to indentify the encoded indicia so that corresponding additional uncoded indicia can be embossed on the card.